Lamp and variable focus shade



Dec. 8, 1936. A .N. G. HoRwrr-r E1'- AL v2,0635504 LAMP AND VARIABLE Focus SHADE Y Fuga Aug. 1s, 1934 2 sheets-sheet 1 INVENTORS /I/a//rmw Har/w# ATTORISQIY Dec. 8, 1936. N. G. HoRw-ITT Er Al.

LAMP AND VARIABLE FOCUS SHADE 2 sheets-sheet 2 Filed Aug. l5, 1954 5 h/ Riadv Y O c E www? www m m www A 17M Lfh/ w Patented Dee. 3,1936

UNireD caries Application August i3, i934, SerialNo. 739,5dd

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This invention relates to a lamp and shade for it. The shade is of exible material, and so constructed that its shape can he changed to maire its iocus variable. An expanding and contracting mounting is provided for the shade to allow for its change of shape. The variable focus is of advantage where the lamp is used in either direct or indirect lighting. By lengthening the focus of the shade, the intensity o1 the lighting is decreased, while its spread is increased, and "Vice Versa. This is especially advantageous in a iloor lamp which can be adjusted in height as well. in a ceiling lamp, it will he valuable rior controlling the height to which a wall may he illuminated. The latter advantage is ideal for picture galleries. y

'the lamp consists of a container within which an electriciight bullo can be mounted. The container is open at one end, and opposite this end and in axial alignment therewith, is mounted the variable focus rehector or shade. By providing suitable supports, the lamp can be used as a door lamp, desk lamp or ceiling lamp.

Other objects and advantages will hecorne apparent upon further study of the description and drawings, in which:-

Fig. i is a vertical section of the lamp, the shade a'nd certain other parts however being shown in elevation. The dot and dash lines show 0f the shade changed in shape from providing a iocus located a short distance down below it, to provide in one case a focus oi innite distance below the shade, and in the other case a. virtual focus above the shade, the latter case dispersing d the light outwardly from the shade.

Fig. 2 is a fragmental plan and horizontal section to an enlarged scale taken along the line i--iof Fig. 3.

Fig. 3 is a. partial section to an enlarged scale through the upper end of the shade and its support, the ball and a portion of the stem ot the supporting member being shown in elevation.l

Fig. d is a sectional plan takenl along the line y of'rig. i.

Fig. 5 is a partial section to an enlarged l'scale taken similarly to Fig. 3, showing a modified support for the shade. i

Fig. 6 is an elevation of the modiiied support, a portion of .the shade being shown with a part broken away. j

Fig. 'l is a top plan of the lower member oi the modlded support, said member being shown by itself.

Fig.l 8 is a top pian of the shade by itself, the solidy lines showingit in its most extended posi'- (iCl. @dt-mm3) tion, that is when it is fiat, while the dot and dash lines show it deformed into conical shape such as is seen in elevation in Fig. i.

Fig. 9 is a partial section of the shade taken along the line @-9 of Fig. 8, with the thumb wheel, gear and shait shown in elevation.

Fig. it is e. partial-section taken along the line lt--id ci Fie. 9.

Fig. il is a broken apart perspective view of a portion oi the shade at its mechanism for producing and maintaining the overlap or the edges oi the shade at the split, with the housing over the driving gear omitted, and

Fig. l2 is an elevation ci the lamp embodied in a door lamp.

The shade itl is formed ci a flexible sheet of material. 'this material should be iiexible with sutcient stiffness and resiliency to oder substantial resistance to change in shape. The term dexilole as used in the claims is intended tobe of such type. Parchment paper is suitable, as is thin sheet metal such as steel or brass. Thin sheets ot phenol condensation products are also suitable. y I

Shade it is formed with an opening it in its central portion and a split extending from said opening to the cuter edge oi the shade. In its dat position, the shade is essentially a split ring with the outer edge of the shade preferably circular in plan. In our preferred form, the edges of the shade at the split ljust touch when the shade is flat, and in this'position, which is the normal position, there are no internal elastic stresses in the shade. The numeral l5 denotes the leit hand edge of the shade (Figs. 8, l0 and l1) at the split, while the numeral it denotes the right hand edge. represent the shade in flat position, right hand edge it cannot he seen, as it is immediately adjacent ieit hand edge it, but below strip il, as seen' in Fig. iii. Strip lll is provided, so that with theshade in dat position, there is no crack or opening InFig. 8, where the solid lines up oi the sheet at the split through which light can shine.. Strip il also ensures that the left hand edge it will always ride over the top of the shade when edges it' and i6 are made to overlap, Which as will he explained later causes the shade f to assume a conical shape. Y

Referring to Figs. 9, liland 11, the mechanism for enacting the overlap of the edges at the split and for retaining them in diilerent amounts of overlap will he seen in detail. Strip Il is provided with a bent back extension i8. Bearings it are punched up' from extension i8 for supporting shaft t@ upon which is fixed driving gear 23.

Extension I 8 is provided with a bent under tongue 2|, having an opening 22 therein. In Fig. 11, tongue 2| is shown in dot and dash lines in extended position before being bent under.

Fixed upon the outer end of shaft 2t is thumb Wheel 24. A washer 25 is provided on shaft 2li to prevent its axial motion outwardly. Enclosing driving gear 23, shaft 2li and bearings I9 is a housing 26, which is butt welded to the top of extension IB.

As noted before, when the shade is dat, split edge III is adjacent split edge I5 but below it, strip I'I coming between said edges. rIhe portion of the shade adjoining edge I6 is provided with holes 2 in line with the teeth of driving gear 23 and adapted for engagement therewith. Open.- ing 22 in tongue 2| is provided to allow clearance for the teeth of gear 23. The portion of the shade adjoining edge I6 extends under strip I'I but over tongue 2i. Strip IT is riveted, to the portion of the shade adjacent edge`I5, coming below said latter portion, with extension It coming over said latter portion. Extension I3 does not lie for its entire width in a plane parallel to strip I'I, its left hand portion, Figs. 10 and 11, being above the plane of top of strip I'I, while its right hand portion is below and in contact with the portion of the shade adjoining edge I6.

A U shaped guide 28 is riveted to the shade at its outer edge, near split edge I6. The lower leg of the guide is fastened beneath the shade, (not seen) after edge IS has been moved at least the width of the guide to the left of tongue 2i, Fig. 11, the upper leg of the guide coming above extension I8, Fig. 8. Another guide 2i! is provided at the inner edge of the shade at opening I4. As seen more clearly in Fig. 9, the upper leg of guide 29 is riveted to the top of strip I'I, with its lower leg coming below the shade at the portion adjoining split edge I6.

Guide 28 also serves as a stop to prevent separation of edges I5 and I6 so that the shade is not opened up at the split. This would occur, referring to Fig. 10, when split edge I6 is moved far enough to the right to be entirely clear of the right hand edge of strip II. Guide 28 prevents this by butting against housing 25 when moved too far to the right.

When thumbv wheel 24 is operated to rotate gear 23 clockwise, as seen in Fig. 10, edge I6 moves to the left and edge I5 to the right, causing the edges of the shade at the split to overlap. The sheet of material comprising the shade is distorted into substantially a cone by causing the edges I5 and I6 to overlap, the fiatness or sharpness of the `cone depending on the amount of overlap. When the overlap is made greater the cone is sharper or has a smaller angle at the apex and vice versa. lThe friction between the sliding parts, especially extension I8, and the resistance to turning of gear 23 and thumb wheel 24 provide a locking action for holding split edges I5 and IB in the different amounts of overlap set.

In simplied form, the shade can be made without the mechanism for effecting the overlap, said overlap being effected by grasping with the fingers, the portions of the shade adjoining the split edges I5 and I6 and pushing them apart or together, the friction of the sliding parts holding the various amounts of overlap set, especially when tongue 2| is not bent down very far, so that it must be sprung to allow the portion of the shade adjoining edge I 6 to pass between it and the bottom of extension I8 to the left, Figs. l0 and 11 shown by the dot and dash lines of Fig. l, marked B, it must be intentionally flexed up or down, as overlap is given to the split edges to determine whether the base of the cone is above or below its apex. In another form, the sheet is formed with internal elastic stress in it tending normally and automatically to cause the base to move down in a lamp of the type of Fig. l as said edges are caused to overlap. With other types of lamp, such as a ceiling lamp, this bias should be for the base to be above the apex. The advantage of the bias is that whenthe shade is changed from at position, it will automatically assume the conical shape most suitable for use with its particular type of lamp.

In Fig. 8, the solid lines show a plan view of the shade in fiat position, corresponding to the flat position B shown in elevation by dot and dash lines in Fig. 1. The dot and dash lines in Fig. 8 show the shade in plan when split edges I5 and I8 have been given a substantial amount of overlap,and the shade has taken on a conical shape. It will be observed that inner opening I4 in the central portion of the shade becomes smaller as the overlap increases and vice versa. As the shade is mounted at its inner edge, that is at said opening, a mechanism must be provided for supporting the shade, that expands and contracts with said inner edge. f

A tubular casing 30 is' provided with a base 3| in the desk type of lamp shown in Fig. 1. Upon base 3l is mounted lamp socket 32, shown holding a light bulb 33. The upper end of casingv 30. which remains open, has three tubular sockets 34 arranged symmetrically within it at the third points of its circumference. Fitting in sockets 34, are the prongs 35 which are twisted about each other at their upper ends to form a post 36. A tubular supporting member 31 has a forced fit over post 36. 'Ihe upper end of member 31 is enlarged to form ball 38. In the type of expanding and contracting mechanism for supporting the shade, illustrated in Figs. 2 and 3, a piece 39, having an annular groove 40 ls mounted on ball 38 and held thereon by nut 4I. Pivot pins 42 are mounted in piece 39 and extend across groove 40 at its third points. Upon each pivot pin 42 is rotatably mounted a finger 43, the pin for each finger being near one end o-f the finger. Located between substantially the middle of each ringer 43 and the inner face of groove 40 is a spring 44,

normally tending t0 force the free end of the finger out of groove 40.

'Ihe outer face of each finger 43 is concave, preferably V shaped. The inner edge of shade I3 engages each finger at its V shaped surface at about the apex of the V. When the area of opening I4 is decreased by increasing the overlap of edges I5 and I6 and thereby the sharpness of the cone angle of the shade, the inner edge of the shade presses back iingers 43 into groove 40 against the pressure of springs 44. In other Words, the surface supporting the shade contracts with the contraction of opening I4. When said opening expands, springs 44 cause the supporting surface to expand with it.

Piece 39 has a central opening 45 in which is 75 necessary friction to hold piece I9 and with' it` shade I3 in the various positions in which they may be set.

A modified type of expanding and contracting' y mechanism for supporting the shade is shownin Figs. 5, 6 and 7, which cmisistsl essentiallyV oi' discs 48 and 49 having their vertical axes in alignment and adapted for relative motion with respect to each other. In the embodiment shown'.

disc 49 is fixed 'against motion, while disc 4I is free to move. Disc 49 is held on ball 38 by nut porting surface.

5U. Extending from the top of ball 38 land fixed thereto is a post' 5i. Disc 48 is loosely mounted on post 5|, a loosely mountedv sleeve 52 iltting between the central hole of said disc and said.v post. I'he upper part of disc 48 is provided with an opening 53 to accommodate washer 54 which nts over post 5i and is normally pressed toward disc 48 by spring 55 which reacts at its upper end against collar 56 formed on post 5I. Disc 49 which has the shape of airustum of a cone, is

provided with radial grooves 51.Y lDisc 48 is provided with tongues'rt corresponding to grooves 5l and entering same. Tonguesr 58 have a vsurface inclining back from the outer edge of disc dt toward its center. The inner edge of shade i3 is gripped Toy the discs along a line determined by the intersection oi the inclined surface oi the tongues 5t and the conical surface of disc dt, see especially Fig. d. As the area oi opening iii oi the shade is decreased, discs it and it are caused to separate, bringing said line oi intersection closer to the center oi the discs, or in other Words 'contracting the supporting surface. When the area oi opening ld increases, spring ti pushes the discs together expanding the sup- Our lamp and shade can vhe embodied in a door lamp as shown in Fig. 12. .Here tubular casing d@ is supported upon telescoping posts dt and dll, .the latter being provided with a base td. Similarly our lamp can he suspended 'from the ceiling. The door lamp of Fig. l2 could he used by attaching base tti tothe ceiling, using posts dit and lit oi substantially less length.

l. li. lamp shade comprising a dexilole sheet ci' material having an opening in' its central portion, said sheet having a split extending from said opening to its outer edge, and nieans rotataioly mounted on said sheet on the portion adjacent one of its split edges and engaging the portion adjoining the other oi the split edges, said means when rotated causing relative motion of the split edges to and from each other for varying the amount oi overlap of the portions adjoining the split edges of the sheet, said means also retaining the split edges in the particular relative position set by its rotation.

2. A lamp shade as claimed in claim l in which the rotatably mounted means is a spur gearvvhose teeth engage the portion adjoining the other ol the split edges from that portion which it is mounted upon, said former portion having a part formed for engaging said teeth.

, 3. A lamp shade having a member for attachment of the shade to a support, said shade formed of a exible sheet oi' material having an opening in its central portion, said sheet having a split rextending from said opening to its outer edge, the variation in overlap of the sheet at the i split controlling the sharpness of the cone' shape of the shade, the area of said opening decreasing as the overlapincrasesfsaid member-'coming causing the second portion's place of contact with theedge ofthe shade at Said openingto expand and contract in accordance with the area of said opening, and spring means normally holding said lportionsinwthe relative position for. maximum expansion of the place of contact.

4. A lamp shade having a member for attachment oi' the shade to a support, said shade formed of a flexible sheet o1' material having an opening in its central portion, said sheet having a split extending from said opening to its outer' edge.

- the variation in overlap of the sheet at the split controlling the sharpness'of the cone shape of the shade, the area of said opening' decreasing as the `overlap increases, said member coming within the opening and comprising a portieriv of greater area than the maximum opening of the shade, and another portion, movable relatively to the first portion, in engagement with the edge of the shade at the opening, said relative rnction causing said second portion to extend variably within the first portion and causing thereby the second portions place oi contact with the edge of the shade at said opening to expand and contract. inV accordance with the area of said opening, and spring means normally holding said expansion of the place ci contact.

5. A lamp shade having a member for attachment oi the shade to a support, said shade formed ol* a :dexihle sheet oi material having an opening in its central portion, said sheet having a split extending from said opening to its outer edge,`the variation in overlap oi the sheet at the split controlling the sharpness oi the cone shape oi the shade, the area of said opening decreasing as the overlap increases, said memher coming 'Withinv theopening and comprising a circular portion oi greater area than the maximum opening of the shade, and another portion, movable relatively to the hrst portion, in engagement with the edge' ci' the shade at the opening, said relative motion causing the second portions place of contact with the edge oi the shade at said'opening to expand and contract in accordance with the area ci said opening, and spring means normally holding said portions in the relative position for maximum expansion of the place oi contact.

6. d lamp shade having a member lor attachment oi the shade to a support, said shade formed of a dexible sheet of material having an opening in. its central portion, said sheet having a split extending from said opening to its outer edge, the variation in overlap of the sheet at the split controlling the sharpness oi the cone shape oi the shade, the area of said opening decreasing as the overlap increases, said member being formed with an annular groove, a plurality oi' fingers plvotally mounted insaid groove tor motion in and out of said groove, and spring means reacting against the member and the lingers lor portions in the relative position for maximum y rio forcing one end oi each oi' the lingers outward t vthe ends oi' the lingers 'engaging the edge of the shade are formed with a depression into which the edge of the shade extends.

8. A lamp shade having a member for attachment of the shade to a support, said shade formed of a exible sheet of material having an opening in its central portion, said sheet having a split extending from said opening to its outer edge, the variation in overlap of the sheet at the split controlling the sharpness of the cone shape of the shade, the area of said opening decreasing as the overlap increases, said member comprising a pair oi discs mounted on the support one above the other with freedom of axial motion to and from each other, and spring means normally holding said discs toward each other. one ot said discs being in the iorm substantially of a frustum of a cone having a plurality of radial grooves extending inward from its conical surface. the other of said discs having a plurality of tongues corresponding to said grooves and entering same, said tongues having a surfacein vclining opposltely to the inclination o! the conical surface and intersecting the conical surface, said discs gripping the edge oi the shade at the opening along a line passing through the intersections of the inclined surfaces of the tongues and the conical surface. said intersections moving radially inwardly or outwardly inA accordance with the arealoi' said opening.

y 9. Alampshadeasclaimedinclaim linwhich the rotatably mounted means is a spur gear whose teeth engage the portion adjoining the other of the split edges from that portion upon which it is mounted, said former portion having a row of spaced holes for engagement with said teeth. l 10. A lamp shade comprising a ilexible sh of material having an opening in its central portion, said sheet having a split extending from said opening to its outer edge, a mounting iixedly attached to said sheet on the portion adjoining one or its split edges, and means movably supported by said mounting engaging the portion Vadjoining the other of the split edges, said means when caused to move on said mounting effecting relative motion of the split edges' to and from cach other for varying the amount oi' overlap of the portions adjoining the split edges of the sheet.

11. A lamp shade as claimed in claim 10 in. which the movable means in addition to eilecting relative motion of the split edges serves as a detent for retaining said edges'in the position 26 set at any time by said means. 

